Solid-state synthesis, dewetting, and magnetic and structural characterization of interfacial Fe x Sn 1− x layers in Sn/Fe(001) thin films

The phase formation sequences in 9Sn/91Fe(001) and 25Sn/75Fe(001) bilayers during thin-film solid-state reactions up to 800°C were investigated using X-ray diffraction, the torque method, and scanning electron microscopy. In both samples, FeSn 2 , FeSn, α-Fe 1− x Sn x , Fe 5 Sn 3 , α-Fe, and β-Sn were sequentially formed at the initiation temperatures T in i ~ 150°C, ~ 300°C, ~ 550°C, ~ 600°C, and ~ 700°C, respectively. Low-temperature transformations were predicted at temperatures T K 1 ~ 150°C and T K 2 ~ 300°C, which are absent in the phase equilibrium diagram of the Fe–Sn system. Solid-state dewetting of the 9Sn/91Fe(001) and 25Sn/75Fe(001) bilayers started at temperatures above 550°C. Overall, this work sheds new light on general chemical mechanisms governing the synthesis of intermetallic phases in Sn/Fe(001) thin films, the phase transformations, and the evolution of the dewetting process of Fe x Sn 1− x films. Graphic abstract